As a type of energy storage device between traditional capacitors and batteries, the supercapacitor has the advantages of energy saving and environmental protection, high power density, fast charging and discharging speed, long cycle life, and so forth. One of the key factors affecting the performance of supercapacitor is the electrode material. Carbon materials, such as carbon nanotube, graphene, activated carbon, and carbon nanocage, are most widely concerned in the application of supercapacitors. The synergistic effect of composites can often obtain excellent results, which is one of the common strategies to increase the electrochemical performance of supercapacitors. To further improve the performance of binary composites, it is a relatively simple method to increase the components as the “bridge” between the two materials to form the ternary composites. The review mainly introduces the current research progress of supercapacitors with pure carbon nanomaterials and multistage carbon nanostructures (composites) as electrodes. The characteristics and application directions of different pure carbon nanomaterials are introduced in detail. Different ways of multilevel structure (material) composite have their own effects on the development of high-performance supercapacitors. We also highlight the recent advances related to these fields and provide our insight into high-energy supercapacitors. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/cey2.219

Carbon nanomaterials and their composites for supercapacitors

The practical applications of skin‐interfaced sensors and devices in daily life hinge on the rational design of surface wettability to maintain device integrity and achieve improved sensing performance under complex hydrated conditions. Various bioinspired strategies have been implemented to engineer desired surface wettability for varying hydrated conditions. Although the bodily fluids can negatively affect the device performance, they also provide a rich reservoir of health‐relevant information and sustained energy for next‐generation stretchable self‐powered devices. As a result, the design and manipulation of the surface wettability are critical to effectively control the liquid behavior on the device surface for enhanced performance. The sensors and devices with engineered surface wettability can collect and analyze health biomarkers while being minimally affected by bodily fluids or ambient humid environments. The energy harvesters also benefit from surface wettability design to achieve enhanced performance for powering on‐body electronics. This review first summarizes the commonly used approaches to tune the surface wettability for target applications toward skin‐interfaced sensors and devices. By considering the existing challenges, one also discusses the opportunities as a small fraction of potential future developments, which can lead to a new class of skin‐interfaced devices for use in digital health and personalized medicine.

Surface Wettability for Skin‐Interfaced Sensors and Devices

MXenes with applications in supercapacitors and secondary batteries: A comprehensive review

Carbonaceous materials as adsorbents for CO2 capture: synthesis and modification

Sodium-chloride-assisted synthesis of nitrogen-doped porous carbon shells via one-step combustion waves for supercapacitor electrodes

The synergism of large surface area, multiscale porous structure, and good conductivity endows hierarchical carbon nanocages with high-level supercapacitive performances. Further nitrogen doping greatly improves the hydrophilicity, which boosts the supercapacitive performances to an ultrahigh specific capacitance of up to 313 F g(-1) at 1 A g(-1).

Jiang Yufei

Papers

Hydrophilic hierarchical nitrogen-doped carbonnanocages for ultrahigh supercapacitive performance